[Differential diagnosis "vertigo and dizziness"]

Vertigo and dizziness are symptoms of interdisciplinary dimension. However, the differentiation and classification of vertigo syndromes also require experience and multidisciplinary knowledge. Since the clinical syndrome is subjective, a detailed analysis of the complaints underlying is required. International disease definitions are an indispensable tool in the differential diagnosis of vertigo syndromes today. With simple diagnostic tools eye movement disorders and nystagmus can be examined and assigned to specific vestibular disorders today. Screening tests (e.g. head impulse test) are now an important instrument in the investigation of patients with vertigo syndromes in case of emergency. With objective diagnostic methods (caloric irrigation, video head impulse test, vestibular evoked myogenic potentials) the degree of functional impairment of the five vestibular receptors can be assessed quantitatively. Furthermore, in vestibulopathies, a receptor and side-specific diagnostic assessment can be performed even with regard to dynamic aspects.

Principles of calcite dissolution in human and artificial otoconia

Human otoconia provide mechanical stimuli to deflect hair cells of the vestibular sensory epithelium for purposes of detecting linear acceleration and head tilts. During lifetime, the volume and number of otoconia are gradually reduced. In a process of degeneration morphological changes occur. Structural changes in human otoconia are assumed to cause vertigo and balance disorders such as benign paroxysmal positional vertigo (BPPV). The aim of this study was to investigate the main principles of morphological changes in human otoconia in dissolution experiments by exposure to hydrochloric acid, EDTA, demineralized water and completely purified water respectively. For comparison reasons artificial (biomimetic) otoconia (calcite gelatin nanocomposits) and natural calcite were used. Morphological changes were detected in time steps by the use of environmental scanning electron microscopy (ESEM). Under in vitro conditions three main dissolution mechanisms were identified as causing characteristic morphological changes of the specimen under consideration: pH drops in the acidic range, complex formation with calcium ions and changes of ion concentrations in the vicinity of otoconia. Shifts in pH cause a more uniform reduction of otoconia size (isotropic dissolution) whereas complexation reactions and changes of the ionic concentrations within the surrounding medium bring about preferred attacks at specific areas (anisotropic dissolution) of human and artificial otoconia. Owing to successive reduction of material, all the dissolution mechanisms finally produce fragments and remnants of otoconia. It can be assumed that the organic component of otoconia is not significantly attacked under the given conditions. Artificial otoconia serve as a suitable model system mimicking chemical attacks on biogenic specimens. The underlying principles of calcite dissolution under in vitro conditions may play a role in otoconia degeneration processes such as BPPV.

Horizontal VOR function shows frequency dynamics in vestibular schwannoma

The objective of this retrospective study was to investigate the horizontal vestibulo-ocular reflex (hVOR) pathway with caloric test (low-frequency hVOR) and video head impulse test (vHIT) (high-frequency hVOR) in patients with sporadic vestibular schwannoma (69 patients, 27-86 years, mean age 58.1 years) and to compare both test methods in terms of their sensitivity and specificity to detect a retrocochlear lesion. Test results with a unilateral weakness (UWCaloric) >25 % (caloric test) or a Mean-GainvHIT <0.79/asymmetry ratio of Gain (AR-GainvHIT) >8.5 % and accompanied refixation saccades (vHIT) were considered abnormal. The overall sensitivity of the caloric test was 72 %. The evaluation of AR-GainvHIT detected more abnormal cases than did Mean-GainvHIT (44 vs. 36 %). In up to 4 %, a normal caloric test result was related to an abnormal vHIT. There was only a moderate correlation of UWCaloric and AR-GainvHIT (r = 0.54, p < 0.05) with a linear regression line intercept/slope of 32.2/0.9 (p < 0.05). Receiver operating characteristics curve analysis exhibited at a UWCaloric of 50 % a vHIT sensitivity/specificity/positive predictive value/negative predictive value of 0.45/0.9/0.94/0.42. Vestibular testing at varying frequencies provides deeper insights into hVOR function and is helpful in detecting a cerebello-pontine lesion. Whereas caloric test yields a high sensitivity for nerve dysfunction, vHIT test reveals a remaining function of hVOR in the high-frequency range.

Results in using the Freiburger monosyllabic speech test in noise without and with hearing aids

The Freiburger Speech Test (FST) has been the gold standard in speech testing by word recognition score in Germany for many years. Recently, it has been demonstrated that for an amount of 104 test-persons there is no significant deviation within the lists. The objective of this study was to determine the percentiles of the distinct measuring situations in quiet and with noise (e.g. applied in hearing aid fitting) and the average benefit using hearing aids. In this prospective study, 623 patients with SNHL and equipped with hearing aids for at least 3 months have been investigated by means of the Freiburger monosyllabic test (FBE) without and with hearing aids and in quiet or with noise (CCITT noise, 65/60 dB signal-noise ratio) in free field conditions at 65 dB to determine the ratio of intelligibility. To investigate the different diagnostic conditions a linear mixed model was applied. The dependent binary variable corresponds to the number of understood syllables. The average age of all subjects was about 72.6 years. The average rate of understanding in the FBE without hearing aids and in quiet was 38.5 %, with hearing aids and in quiet 67.7 %, without hearing aids and with noise 22.4 %, and with hearing aids and with noise 39.8 %. All results were presented with the depending confidence intervals. The extent of hearing loss and the quality of hearing aid fitting can be successfully measured using the FST in quiet and with background noise (CCITT noise). In quiet, an average hearing improving gain of 29.2 % points and with noise a gain of 17.4 % points could be estimated with a successful hearing aid fitting.

[Video head impulse test or caloric irrigation? Contemporary diagnostic tests for vestibular schwannoma]

The video head impulse test (vHIT) is a new method for investigating vestibular function that is currently poorly studied in terms of its value for clinical diagnosis in otolaryngology. Both the caloric irrigation and vHIT serve to evaluate the horizontal vestibulo-ocular reflex. In the present study, caloric irrigation and vHIT were compared in 46 patients with vestibular schwannoma. Caloric irrigation exhibits a higher sensitivity than vHIT (72% versus 41%) and both tests show only a moderate correlation. Tumor size and hearing level was significantly correlated with caloric abnormalities but not with vHIT findings. Since caloric irrigation and vHIT measure the hVOR in low and high frequency ranges, respectively, these tests have to be considered complementary and are valuable in both diagnostics and therapeutic decisions.

[Evaluation of the Freiburg monosyllabic speech test in background noise]

BACKGROUND

The Freiburg speech test has been the gold standard in speech audiometry in Germany for many years. Previously, however, this test had not been evaluated in assessing the effectiveness of a hearing aid in background noise. Furthermore, the validity of particular word lists used in the test has been questioned repeatedly in the past, due to a suspected higher variation within these lists as compared to the other word list used.

PATIENTS AND METHODS

In this prospective study, two groups of subjects [normal hearing control subjects and patients with SNHL (sensorineural hearing loss) that had been fitted with hearing aid] were examined. In a first group, 113 control subjects with normal age- and gender-related pure tone thresholds were assessed by means of the Freiburg monosyllabic test under free-field conditions at 65 dB. The second group comprised 104 patients that had been fitted with hearing aids at least 3 months previously to treat their SNHL. Members of the SNHL group were assessed by means of the Freiburg monosyllabic test both with and without hearing aids, and in the presence or absence of background noise (CCITT-noise; 65/60 dB signal-noise ratio, in accordance with the Comité Consultatif International Téléphonique et Télégraphique), under free-field conditions at 65 dB.

RESULTS

The first (control) group exhibited no gender-related differences in the Freiburg test results. In a few instances, inter-individual variability of responses was observed, although the reasons for this remain to be clarified. Within the second (patient) group, the Freiburg test results under the four different measurement conditions differed significantly from each other (p>0.05). This group exhibited a high degree of inter-individual variability between responses. In light of this, no significant differences in outcome could be assigned to the different word lists employed in the Freiburg speech test.

CONCLUSION

The Freiburg monosyllabic test is able to assess the extent of hearing loss, as well as the effectiveness of a fitted hearing aid, in the presence or absence of background-noise (CCITT-noise). The present study could not evidence statistically significant differences in outcome when using the different word lists in this test battery.

Gentamicin-induced structural damage of human and artificial (biomimetic) otoconia

CONCLUSIONS

Gentamicin causes irreversible structural damage of human and artificial otoconia by progressive dissolution of calcite. The inner architecture of otoconia is strongly affected by degradation scenarios during gentamicin exposure. Artificial otoconia can be used as a model system mimicking the chemical attacks for detailed investigations.

OBJECTIVES

To investigate the chemical interactions of gentamicin with natural calcite and human and artificial otoconia under in vivo conditions.

METHODS

Pure calcite crystals and artificial and human otoconia were exposed to gentamicin injection solutions at various concentrations. Morphological changes were observed in time steps by the use of environmental scanning electron microscopy (ESEM).

RESULTS

Dissolution of pure calcite crystals results in the formation of well oriented nanoshoots indicating an irreversible chemical reaction with gentamicin. Human and artificial otoconia reveal irreversible structural changes of their surface areas as well as of their inner structure, resulting in characteristic changes at different gentamicin concentrations. Minor changes are first observed by surface alterations and dissolution of calcite in the belly region. Major changes result in further reduction of the belly area reaching the center of symmetry. Finally, a complete dissolution of the branches takes place. Artificial otoconia provide detailed insight into surface alterations.

[Dizziness from the viewpoint of otorhinolaryngology]

Dizziness is a common symptom in daily clinical practice. Dizziness and vertigo affect the quality of life as they are associated with the risk of falls leading to limited ability of independent locomotion and thus to a reduction in social contact. The source of problems with dizziness is localized in the area of visual, somatosensory and vestibular sense inputs. The ear nose and throat (ENT) specialist is involved in an interdisciplinary context to elucidate and treat peripheral vestibular disorders. The subjective symptoms of dizziness have to be clarified by taking a careful patient history. By means of objective tests (cVEMP, oVEMP, video-head impulse test) the ENT specialist is able to selectively analyze the function of the five vestibular receptors; therefore, a topological assignment in peripheral vestibulopathy is possible. The exact diagnosis is a prerequisite for a specific therapy and many diseases can be evidence-based, safe and effectively treated.

[The video head impulse test: first clinical experiences]

BACKGROUND

Side-specific test procedures are mandatory in order to assess the function of peripheral vestibular receptors. Semicircular canals (SCC) and vestibulo-ocular reflex (VOR) can be tested by the Halmagyi and Curthoy head impulse test (HIT) and recently by means of the video head impulse test (vHIT). The vHIT procedure is a new method to measure eye and head velocity during brief and rapid head impulses. This method provides objective information of VOR and detects both overt and covert catch-up saccades.

MATERIALS AND METHODS

As clinical experiences with vHIT are limited, in this study the horizontal VOR (hVOR) was examined by means of the vHIT in 142 consecutive patients with acute or chronic vestibular syndrome.

RESULTS

A total of 20 healthy volunteers served as a control group and exhibited a normal average VOR gain of 0.97 ± 0.09 without re-fixation saccades. In patients, 47.6% showed a pathological vHIT whereas 52.4% revealed a normal test result. Covert catch-up saccades could be revealed in 13.7% by means of vHIT whereas in 86.3% overt catch-up saccades alone or in combination with covert catch-up saccades were found in the majority of catch-up saccades in peripheral vestibular disorders.

CONCLUSIONS

By means of the vHIT it is possible to obtain a side-specific and quantitative assessment of hVOR. Video-head impulse test is a reliable tool for vestibular testing even in bedside examinations of patients suffering from dizziness.

Incidence and localization of abnormal mucosa findings in patients consulting ENT outpatient clinics and data analysis of a cancer registry

For patients without symptoms and at risk, there is no established early detection program to discover carcinomas of the upper aerodigestive tract in the sense of secondary prevention. Such type of prevention seems even more desirable because the chances for a cure and the quality of life are strongly dependent on the stage of the tumor and the time of the initial diagnosis. Six hundred and eight patients without symptoms but at least one of the self-reported risk factors "smoking", "alcohol consumption" or "reflux" were examined with an endoscope or an optical microscope for pathological findings in the upper aerodigestive tract once a year. In addition, the incidence of malignancies of the upper aerodigestive tract between 2001 and 2010 was determined through the Cancer Registry of Schleswig-Holstein. Tissue samples were taken from 18 of the 608 patients. Eleven patients (1.8%) had a squamous cell carcinoma. Another patient suffered from non-Hodgkin's lymphoma and one from larynx tuberculosis. The ratio of detected malignancies in the oral cavity and the oropharynx on the one hand and the hypopharynx and larynx, which can only be examined by endoscopes, on the other hand were in our cohorts and in our survey according to the cancer registry was 5/6. The above-described methods allow examining risk patients easily and safely. According to current publications, the ratio of the found malignancies exceeds the expected ratio significantly, which presumably was caused by the examination targeting patients at risk. Due to the expanded examination area using optical instruments more than doubles the rate of discoverable malignancies compared to the limitations posed by the examination of directly visible areas of the oral cavity of the oropharynx.

[The Mini-Audio-Test (MAT). Screening inventory for hearing loss starting at the age of 50]

BACKGROUND

Progredient hearing loss is a common symptom, which is hard to detect early. This study presents an assessment to face this problem.

METHODS

1,159 subjects between the age of 50 and 75 have been investigated by a 12 question profile about their hearing in different situations. The answers have been rated by weighted points and compared with the pure-tone audiogram of the subjects.

RESULTS

6 of the 12 questions were suitable to detect a hearing loss of 25 dB in one of the 4 frequencies 0,5-1-2-4 kHz. For subjects under age of 60 a cutoff value of 3, for subjects aged 60 years or older a cutoff value of 2 points could be set for the 6 questions including "Mini-Audio-Test" (MAT).

DISCUSSION

The "Mini-Audio-Test" is able to detect a hearing loss of 25 dB at least in one of the 4 frequencies by a sensitivity of 78%, 95% confidence interval (71,8%, 83,2%), for the younger group of subjects and by 69%, 95% confidence interval (66,0%, 72,6%), for the older one. Subjects with a pathological score should be examined by an ENT-physician.

[Isolated functional loss of the lateral semicircular canal in vestibular neuritis]

Today, modern tools in vestibular testing are feasible to provide information about functional status of all five peripheral vestibular receptors. Isolated or combined loss of crista and macula receptor function can be determined in the diagnostic process. We describe a seldom case of isolated functional loss of lateral semicircular canal receptor function in a 55-year-old patient. Whereas there was no ispilateral caloric response and video head impulse test revealed a catch-up saccade, air-conducted (AC) cervical and ocular vestibular-evoked myogenic potentials (cVEMP, oVEMP), subjective visual vertical and MRI were normal.

[Diagnosis of vertigo: keep an eye on central eye movement disorders]

With specialist knowledge ophthalmologists can make a valuable contribution to the interdisciplinary work-up of patients with vertigo as the leading symptom. The neuro-ophthalmological examination of eye movements by an ophthalmologist and/or orthoptist is an important contribution because the various vertigo syndromes can only be correctly evaluated by a combined examination of the vestibular and ocular motor systems. If the ophthalmologist is the first doctor to examine a patient suspected disorders from other specialist fields can be indicated, in particular neurology and otorhinolaryngology. When taking the patient history the ophthalmologist should inquire about the type and duration of the vertigo, triggering or modifying factors and accompanying symptoms. This is followed by a systematic examination of the eye position and the different types of eye movements, the head-impulse test and a special examination to check for the presence of nystagmus.

[Falls and fall risk factors. Are they relevant in ENT outpatient medical care?]

BACKGROUND AND OBJECTIVE

The risk of falling increases with age. The problem of falls in medical care constantly rises in priority due to demographic changes in Germany. Therefore, the risk of falling should be assessed in all patients. The present study was intended to evaluate the frequency of falls in daily ENT outpatient medical care and the importance of risk factors.

PATIENTS/METHODS

A multicentre study was performed in six outpatient facilities based on a survey of falls and fall risk factors in patients living at home (n = 673) aged 60 years and older.

RESULTS

Falls are a frequent problem in the elderly. A total of 23% had one and 13.7% more than one fall within the previous year. Of these, 15% suffered injury, while only 13% used some form of fall prevention. Joint pain and problems of the hip and lower extremities (42.6%), abnormal gait (41.3%), dizziness and balance disorders (38%) as well as impaired activities of daily living (35%) are the most common risk factors for falls and multiple falls in all age groups. Impaired hearing is a fall risk factor in elderly patients.

CONCLUSIONS

Falls are a frequent problem in patients in ENT outpatient medical care. Fall prevention is advisable in the context of an interdisciplinary approach.

[Receptor function of the semicircular canals. Part 2: pathophysiology, diseases, clinical findings and treatment aspects]

Perturbation of semicircular canal function may result in a pathological angular vestibulo-ocular reflex (aVOR). The resulting impairment in gaze stabilization is perceived as "vertigo" or "dizziness" and may occur following receptor function impairment of all three semicircular canals. The head impulse test reveals hidden (covert-catchup) or visible (overt-catchup) saccades in disturbances of semicircular function. Most peripheral vestibular disorders can be treated conservatively. There are surgical treatment options for some diseases, such as intractable benign paroxysmal positional vertigo and superior semicircular canal dehiscence. Vestibular training promotes central reorganization of the VOR. Impaired semicircular receptor function, in particular bilateral vestibulopathy, may affect spatial orientation and cognitive processes. Balance prostheses could serve as a replacement for receptors in the future.

Ocular vestibular evoked myogenic potentials to air conduction (AC oVEMP): useful in clinical practice?

Cervical vestibular-evoked myogenic potential (cVEMP) and ocular VEMP (oVEMP) stimuli can be used to measure otolith function using air (AC) and bone conducted (BC) stimuli. Cervical VEMPs reflect saccular function and can be recorded using air conduction (AC), whereas oVEMPs reflect probably predominantly utricular function. Air- and bone-conducted vibration can be used, because AC oVEMP methodology seems to be fast and simple in clinical practice to measure otolith function. In this study we discuss the advantages and problems of AC oVEMP stimulation. AC oVEMP can be easily and quickly obtained within a few seconds. N10 (first negative peak) and p15 (first positive peak) latencies may be used as parameters for clinical interpretation but amplitude fluctuations are relatively large. For daily clinical use of VEMP visualization in a normogram seems feasible. Especially the AC oVEMP methodology (100 dB nHL, tone burst 500 Hz) is fast and efficient in clinical practice to measure otolith function, predominantly utricular function.

[Prevalence of abnormal mucosal findings in patients in HNO practices]

OBJECTIVE

To date, no secondary prevention program is in place for patients carrying an increased risk for developing head and neck cancer (HNSCC). In terms of successful, long-term curative therapy and increased quality of life, it would be useful to detect such diseases at an early stage.

PATIENTS AND METHODS

A total of 370 patients with at least one risk factor such as "smoking", "alcohol", or "reflux disease" and without any symptoms were examined during a 1-year period using standard HNO methods (e. g. endoscopy) for suspicious alterations of the mucosa of the upper aerodigestive tract.

RESULTS

In 13 (3.5%) of all 370 cases a biopsy was taken for further diagnosis. Squamous cell carcinoma was found in eight cases, while one further patient was suffering from non-Hodgkin lymphoma.

CONCLUSIONS

It is simple and safe to examine patients at risk of developing HNSCC by standard HNO methods. The rate of detected carcinomas is much higher than in former investigations, likely because our survey focused only on patients with specific risk factors.

[Air conducted ocular VEMP: II. First clinical investigations]

BACKGROUND

Vestibular-evoked myogenic potentials (VEMP) are widely used to assess vestibular function. Air conducted (AC) cervical VEMP (cVEMP) reflect sacculus and inferior vestibular nerve function. Ocular VEMP (oVEMP) however has been hardly examined up to now. In recent studies it has been assumed that AC oVEMP probably reflects superior vestibular nerve function. The aim of this pilot study was to evaluate clinical application of the AC oVEMP.

MATERIAL AND METHODS

AC oVEMP were recorded in patients with peripheral vestibular disorders (n=21). In addition thermal irritation and head impulse test were performed and AC cVEMP were recorded. For intense AC-sound stimulation tone bursts (500 Hz) with 100 dB nHL were used.

RESULTS

In peripheral vestibular disorders AC oVEMP and AC cVEMP could be classified into: • type 1 (inferior vestibular neuritis) with loss of AC oVEMP but normal AC cVEMP, • type 2, probable type of superior vestibular neuritis, showing present AC cVEMP but loss of AC oVEMP, • type 3, probable complete vestibular neuritis, without AC oVEMP and AC cVEMP.

CONCLUSIONS

AC oVEMP may be used as an appropriate test for clinical investigation in patients with vestibular disorders. AC oVEMP is an additional, essential test for assessing otolith function beside AC cVEMP. Further vestibular test are necessary for precise clinical interpretation.

[Air conducted ocular VEMP: I. Determination of a method and application in normal patients]

BACKGROUND

Air conducted (AC) cervical vestibular evoked myogenic potentials (AC cVEMP) and air conducted ocular VEMP (AC oVEMP) may be used for measurement of otolith function. However AC oVEMP are few examined till now. The aim of this pilot study was to apply a method for use of AC oVEMP in clinical practice.

PATIENTS AND METHODS

AC oVEMP were recorded in healthy voluntary people (n=20) using intense AC-sound stimulation (500 Hz tone bursts, 100 dB nHL). Thermal irrigation and AC cVEMP were normal as including criteria. Values were evaluated statistically.

RESULTS

AC oVEMP were recorded in all healthy patients. Mean and standard deviation for the first negative peak was 11.35±1.00 ms and for the first negative peak 16.30±1.10 ms. The mean amplitudes were 7.70±4.50 μV. The stability of n10 and p15 component was the same.

CONCLUSIONS

AC oVEMP can be easy and fast obtained. N10 and p15 latencies may used as parameter for clinical interpretation. Amplitude fluctuations are relatively large. Results can be used in further clinical investigation of AC oVEMP.

Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus

Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

[Recording cervical and ocular vestibular evoked myogenic potentials. Part 2: influencing factors, evaluation of findings and clinical significance]

VEMP measurements are subject to various influencing factors: patient age, threshold, sound intensity and frequency. Using air (AC) and bone conduction (BC) the vestibular receptors and afferents of the otolith organs can be activated to varying degrees. Recordings of cervical (cVEMP) and ocular VEMP (oVEMP) are clinically possible. AC-cVEMP are primarily an indicator of the sacculocollic reflex pathway. Together with findings on the vestibuloocular reflex (VOR) and complimentary otolith tests, VEMP enable otolith function analysis of each side separately. In addition, the distinction between combined or isolated canal and otolith dysfunction in terms of subtyping and patterns of damage in mono- and bilateral disorders, such as vestibular neuritis or bilateral vestibulopathy, is possible. Moreover, VEMP is relevant in terms of prognostic and therapeutic considerations as well as expert assessments.